Solvolysis of biomass using solvent from a bioreforming process

ABSTRACT

The present invention provides processes for deconstructing biomass using a solvent produced in a bioreforming reaction.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.13/339,720, filed Dec. 29, 2011 which claims the benefit of U.S.Provisional Application No. 61/428,472 filed on Dec. 30, 2010.

TECHNICAL FIELD

The present invention is directed to a process in which liquids producedin a bioreforming process are used in the solvent-facilitateddeconstruction of biomass.

BACKGROUND OF THE INVENTION

The increasing cost of fossil fuel and environmental concerns havestimulated worldwide interest in developing alternatives topetroleum-based fuels, chemicals, and other products. Biomass materialsare a possible renewable alternative.

Lignocellulosic biomass includes three major components. Cellulose, aprimary sugar source for bioconversion processes, includes highmolecular weight polymers formed of tightly linked glucose monomers.Hemicellulose, a secondary sugar source, includes shorter polymersformed of various sugars. Lignin includes phenylpropanoic acid moietiespolymerized in a complex three dimensional structure. The resultingcomposition of lignocellulosic biomass is roughly 40-50% cellulose,20-25% hemicellulose, and 25-35% lignin, by weight percent.

No cost-effective process currently exists for efficiently convertingcellulose, hemicellulose, and lignin to components better suited forproducing fuels, chemicals, and other products. This is generallybecause each of the lignin, cellulose and hemicellulose componentsdemand distinct processing conditions, such as temperature, pressure,catalysts, reaction time, etc. in order to effectively break apart itspolymer structure.

One can use expensive organic solvents such as acetone, ethanol,4-methyl-2-pentanone, and solvent mixtures, to fractionatelignocellulosic biomass into cellulose, hemicellulose, and ligninstreams (Paszner 1984; Muurinen 2000; and Bozell 1998). Using thisprocess, the organic solvents dissolve some of the lignin such that itis possible to separate the dissolved lignin from the solid celluloseand hemicellulose. To the extent that the lignin can be separated, itcan be burned for energy or can be converted with a ZSM-5 catalyst toliquid fuel compounds, such as benzene, toluene, and xylene (Thring2000).

After removing the lignin from biomass, one can depolymerize thedelignified lignocellulose by acid catalytic hydrolysis using acids suchas sulfuric acid, phosphoric acid, and organic acids. Acid catalytichydrolysis produces a hydrolysate product containing sugars, acid, andother components such as polyols, oligosaccharides, organic acids,lignin, and proteins. The hydrolysates can be separated using knownfractionation processes. One can alternatively employ a specialized acidcatalytic hydrolysis technology developed by Arkenol, Inc. to convertcellulose and hemicellulose in biomass to sugars using highlyconcentrated acid and to separate sugars from acid using a simulatedmoving bed process (Farone 1996).

Cellulose and hemicellulose can be used as feedstock for variousbioreforming processes, including aqueous phase reforming (APR) andhydrodeoxygenation (HDO)—catalytic reforming processes that, whenintegrated with hydrogenation, can convert cellulose and hemicelluloseinto hydrogen and hydrocarbons, including liquid fuels and otherchemical products. APR and HDO methods and techniques are described inU.S. Pat. Nos. 6,699,457; 6,964,757; 6,964,758; and 7,618,612 (all toCortright et al., and entitled “Low-Temperature Hydrogen Production fromOxygenated Hydrocarbons”); U.S. Pat. No. 6,953,873 (to Cortright et al.,and entitled “Low-Temperature Hydrocarbon Production from OxygenatedHydrocarbons”); U.S. Pat. Nos. 7,767,867 and 7,989,664 and U.S.Application Ser. No. 2011/0306804 (all to Cortright, and entitled“Methods and Systems for Generating Polyols”). Various APR and HDOmethods and techniques are described in U.S. Patent Application Ser.Nos. 2008/0216391; 2008/0300434; and 2008/0300435 (all to Cortright andBlommel, and entitled “Synthesis of Liquid Fuels and Chemicals fromOxygenated Hydrocarbons”); U.S. Patent Application Ser. No. 2009/0211942(to Cortright, and entitled “Catalysts and Methods for ReformingOxygenated Compounds”); U.S. Patent Application Ser. No. 2010/0076233(to Cortright et al., and entitled “Synthesis of Liquid Fuels fromBiomass”); International Patent Application No. PCT/US2008/056330 (toCortright and Blommel, and entitled “Synthesis of Liquid Fuels andChemicals from Oxygenated Hydrocarbons”); and commonly owned co-pendingInternational Patent Application No. PCT/US2006/048030 (to Cortright etal., and entitled “Catalyst and Methods for Reforming OxygenatedCompounds”), all of which are incorporated herein by reference.

Biomass must be deconstructed to less complex oxygenated compounds priorto use as feedstock for bioreforming processes. There remains a need forcost-effective methods for separating biomass into streams suitable foruse in APR, HDO and other bioreforming processes.

SUMMARY

The invention provides methods for making a biomass hydrolysate. Themethod generally involves: (1) catalytically reacting water and awater-soluble C₂₊O₁₊ oxygenated hydrocarbon in a liquid or vapor phasewith H₂ in the presence of a deoxygenation catalyst at a deoxygenationtemperature and a deoxygenation pressure to produce a biomass processingsolvent comprising a C₂₊O₁₋₃ hydrocarbon in a reaction stream; and (2)reacting the biomass processing solvent with a biomass component at adeconstruction temperature and a deconstruction pressure to produce abiomass hydrolysate comprising at least one member selected from thegroup consisting of a water-soluble lignocellulose derivative, awater-soluble cellulose derivative, a water-soluble hemicellulosederivative, a carbohydrate, a starch, a monosaccharide, a disaccharide,a polysaccharide, a sugar, a sugar alcohol, an alditol and a polyol.

One aspect of the invention is the composition of the biomass processingsolvent. In one embodiment, the biomass processing solvent includes amember selected from the group consisting of an alcohol, ketone,aldehyde, cyclic ether, ester, diol, triol, hydroxy carboxylic acid,carboxylic acid, and a mixture thereof.

The invention also provides a method of making a biomass hydrolysatecomprising the steps of: (1) providing water and a water-solubleoxygenated hydrocarbon comprising a C₂₊O₁₊ hydrocarbon in an aqueousliquid phase or a vapor phase; (2) providing H₂; (3) catalyticallyreacting in the liquid or vapor phase the oxygenated hydrocarbon withthe H₂ in the presence of a deoxygenation catalyst at a deoxygenationtemperature and deoxygenation pressure to produce an oxygenatecomprising a C₂₊O₁₋₃ hydrocarbon in a reaction stream; (4) catalyticallyreacting in the liquid or vapor phase the oxygenate in the presence of acondensation catalyst at a condensation temperature and condensationpressure to produce a biomass processing solvent comprising one or moreC₄₊ compounds; and (5) reacting the biomass processing solvent with abiomass component at a deconstruction temperature and a deconstructionpressure to produce a biomass hydrolysate comprising at least one memberselected from the group consisting of a water-soluble lignocellulosederivative, a water-soluble cellulose derivative, a water-solublehemicellulose derivative, a carbohydrate, a starch, a monosaccharide, adisaccharide, a polysaccharide, a sugar, a sugar alcohol, an alditol,and a polyol.

The biomass processing solvent may include a member selected from thegroup consisting of an alkane, alkene and an aromatic. In oneembodiment, the member is selected from the group consisting of benzene,toluene and xylene.

In one embodiment, the condensation catalyst is a zeolite.

The invention also provides a method of deconstructing biomass. Themethod generally includes reacting a biomass slurry with a biomassprocessing solvent comprising a C₂₊O₁₋₃ hydrocarbon at a deconstructiontemperature between about 80° C. and 350° C. and a deconstructionpressure between about 100 psi and 2000 psi to produce a biomasshydrolysate comprising at least one member selected from the groupconsisting of a water-soluble lignocellulose derivative, water-solublecellulose derivative, water-soluble hemicellulose derivative,carbohydrate, starch, monosaccharide, disaccharide, polysaccharide,sugar, sugar alcohol, alditol, and polyol, wherein the biomassprocessing solvent is produced by catalytically reacting in the liquidor vapor phase an aqueous feedstock solution comprising water and awater-soluble oxygenated hydrocarbons comprising a C₂₊O₁₊ hydrocarbonwith H₂ in the presence of a deoxygenation catalyst at a deoxygenationtemperature and deoxygenation pressure.

The oxygenated hydrocarbon may include a member selected from the groupconsisting of a lignocellulose derivative, a cellulose derivative, ahemicellulose derivative, a carbohydrate, a starch, a monosaccharide, adisaccharide, a polysaccharide, a sugar, a sugar alcohol, an alditol,and a polyol.

Another aspect of the invention is that a portion of the biomasshydrolysate produced by the process above is recycled and combined withthe biomass slurry.

The biomass processing solvent may comprise a member selected from thegroup consisting of an alcohol, ketone, aldehyde, diol, triol, cyclicether, ester, hydroxy carboxylic acid, carboxylic acid, and a mixturethereof. In one embodiment, the biomass processing solvent comprises amember selected from the group consisting of methanol, ethanol, n-propylalcohol, isopropyl alcohol, butyl alcohol, pentanol, hexanol,cyclopentanol, cyclohexanol, 2-methylcyclopentanol, hydroxyketones,cyclic ketones, acetone, propanone, butanone, pentanone, hexanone,2-methyl-cyclopentanone, ethylene glycol, 1,3-propanediol, propyleneglycol, butanediol, pentanediol, hexanediol, methylglyoxal, butanedione,pentanedione, diketohexane, hydroxyaldehydes, acetaldehyde,propionaldehyde, butyraldehyde, pentanal, hexanal, formic acid, aceticacid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid,lactic acid, glycerol, furan, tetrahydrofuran, dihydrofuran, 2-furanmethanol, 2-methyl-tetrahydrofuran, 2,5-dimethyl-tetrahydrofuran,2-ethyl-tetrahydrofuran, 2-methyl furan, 2,5-dimethyl furan, 2-ethylfuran, hydroxylmethylfurfural, 3-hydroxytetrahydrofuran,tetrahydro-3-furanol, 5-hydroxymethyl-2(5H)-furanone,dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydro-2-furoic acid,dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydrofurfuryl alcohol,1-(2-furyl)ethanol, and hydroxymethyltetrahydrofurfural, isomersthereof, and combinations thereof.

The deoxygenation catalyst is capable of deoxygenating water solubleoxygenated hydrocarbons to produce the biomass processing solvent. Thedeoxygenation catalyst comprises a support and a member adhered to thesupport selected from the group consisting of Re, Cu, Fe, Ru, Ir, Co,Rh, Pt, Pd, Ni, W, Os, Mo, Ag, Au, an alloy thereof, and a combinationthereof. It may further comprise a member selected from the groupconsisting of Mn, Cr, Mo, W, V, Nb, Ta, Ti, Zr, Y, La, Sc, Zn, Cd, Ag,Au, Sn, Ge, P, Al, Ga, In, Tl, and a combination thereof. Thedeoxygenation catalyst may have an active metal function and an acidicfunction. The support may be a member selected from group consisting ofcarbon, silica, alumina, zirconia, titania, tungsten, vanadia,heteropolyacid, kieselguhr, hydroxyapatite, chromia, zeolite, andmixtures thereof. The support may be a member selected from the groupconsisting of tungstated zirconia, tungsten modified zirconia, tungstenmodified alpha-alumina, or tungsten modified theta alumina.

Another aspect of the invention is that the H₂ may be in situ generatedH₂, external H₂, or recycled H₂. The H₂ may be generated in situ bycatalytically reacting in a liquid phase or vapor phase a portion of thewater and the oxygenated hydrocarbon in the presence of an aqueous phasereforming catalyst at a reforming temperature and reforming pressure.

In one embodiment, the aqueous phase reforming catalyst may comprise asupport and a member adhered to the support selected from the groupconsisting of Fe, Ru, Os, Ir, Co, Rh, Pt, Pd, Ni, an alloy thereof, anda combination thereof. The aqueous phase reforming catalyst may furthercomprise a member selected from the group consisting of Cu, B, Mn, Re,Cr, Mo, Bi, W, V, Nb, Ta, Ti, Zr, Y, La, Sc, Zn, Cd, Ag, Au, Sn, Ge, P,Al, Ga, In, Tl, an alloy thereof, and a combination thereof. In anotherembodiment, the aqueous phase reforming catalyst and the deoxygenationcatalyst are combined into a single catalyst.

The aqueous phase reforming and deoxygenation reactions are conducted ata temperature and pressure where the thermodynamics are favorable. Inone embodiment, the reforming temperature is in the range of about 100°C. to about 450° C. or about 100° C. to about 300° C., and the reformingpressure is a pressure where the water and the oxygenated hydrocarbonare gaseous. In another embodiment, the reforming temperature is in therange of about 80° C. to 400° C., and the reforming pressure is apressure where the water and the oxygenated hydrocarbon are liquid.

The deoxygenation temperature may be greater than 120° C., or 150° C.,or 180° C., or 200° C., and less than 325° C., or 300° C., or 280° C.,or 260° C., or 240° C., or 220° C. The deoxygenation pressure may begreater than 200 psig, or 365 psig, or 500 psig or 600 psig, and lessthan 2500 psig, or 2250 psig, or 2000 psig, or 1800 psig, or 1500 psig,or 1200 psig, or 1000 psig. The deoxygenation temperature may also be inthe range of about 120° C. to 325° C., and the deoxygenation pressure isat least 0.1 atmosphere. In other embodiments, the deoxygenationtemperature is in the range of about 120° C. to about 325° C. or about200° C. to 280° C., and the deoxygenation pressure is between about 365psig and about 2500 psig or about 600 psig and 1800 psig.

In one embodiment, the APR catalyst and the deoxygenation catalyst arecombined into a single catalyst. In this aspect, the reformingtemperature and deoxygenation temperature may be in the range of about100° C. to 325° C., or about 120° C. to 300° C., or about 200° C. to280° C., and the reforming pressure and deoxygenation pressure may be inthe range of about 200 psig to 1500 psig, or about 200 psig to 1200psig, or about 200 psig to 725 psig.

In another embodiment, the step of reacting a biomass slurry with abiomass processing solvent is performed in the same reactor as the stepof catalytically reacting the aqueous feedstock solution with H₂ in thepresence of a deoxygenation catalyst. The deconstruction temperature anddeoxygenation temperature may be in the range of about 100° C. to 325°C., about 120° C. to 300° C., or about 200° C. to 280° C., and thedeconstruction pressure and deoxygenation pressure may be in the rangeof about 200 psig to 1500 psig, about 200 psig to 1200 psig, or about600 psig to 1800 psig.

Another aspect of the invention includes the step of dewatering thebiomass hydrolysate.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow diagram illustrating a process for converting biomassto liquid fuels.

FIG. 2 is a flow diagram illustrating a process for converting biomassto liquid fuels using a biomass processing solvent derived from theconversion of biomass hydrolysate in an APR/HDO process.

FIG. 3 illustrates the results of biomass deconstruction using benzene,toluene, and 4-methyl-2-pentanone.

FIG. 4 illustrates the major compounds in an APR aqueous productsolvent.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides processes for hydrolyzing ordeconstructing biomass using a biomass processing solvent produced in abioreforming process. The resulting product stream includes a biomasshydrolysate that can be further processed in a bioreforming process toprovide the biomass processing solvent and a product stream for furtherconversion to desired compounds. The bioreforming process anddeconstruction process may occur separately in different reactors ortogether in a single reactor, and generally occur in steady-state aspart of a continuous process.

As used herein, the term “biomass” refers to, without limitation,organic materials produced by plants (such as leaves, roots, seeds andstalks), and microbial and animal metabolic wastes. Common biomasssources include: (1) agricultural residues, including corn stover,straw, seed hulls, sugarcane leavings, bagasse, nutshells, cotton gintrash, and manure from cattle, poultry, and hogs; (2) wood materials,including wood or bark, sawdust, timber slash, and mill scrap; (3)municipal solid waste, including recycled paper, waste paper and yardclippings; and (4) energy crops, including poplars, willows, switchgrass, miscanthus, sorghum, alfalfa, prairie bluestream, corn, soybean,and the like. The term also refers to the primary building blocks of theabove, namely, lignin, cellulose, hemicellulose and carbohydrates, suchas saccharides, sugars and starches, among others.

As used herein, the term “bioreforming” refers to, without limitation,processes for catalytically converting biomass and other carbohydratesto lower molecular weight hydrocarbons and oxygenated compounds, such asalcohols, ketones, cyclic ethers, esters, carboxylic acids, aldehydes,diols and other polyols, using aqueous phase reforming, hydrogenation,hydrogenolysis, hydrodeoxygenation and/or other conversion processesinvolving the use of heterogeneous catalysts. Bioreforming also includesthe further catalytic conversion of such lower molecular weightoxygenated compounds to C₄₊ compounds.

The deconstruction process uses a biomass processing solvent or solventmixture produced in a bioreforming process. One such process isillustrated in FIG. 1. First, in the deconstruction process, a biomassslurry is combined with a biomass processing solvent or solvent mixtureproduced in a bioreforming process. The biomass slurry may include anytype of biomass that has been chopped, shredded, pressed, ground orprocessed to a size amenable for conversion. The biomass processingsolvent or solvent mixture may contain a wide range of oxygenates, suchas ketones, alcohols, cyclic ethers, aldehydes, acids, esters, diols,and other polyols, and/or C₄₊ hydrocarbons, such as C₄₊ alkanes, C₄₊alkenes, and aromatic compounds, including benzene, toluene, xylene. Ina preferred embodiment, the biomass processing solvent or solventmixture is derived from the biomass hydrolysate or, as illustrated inFIGS. 1 and 2, from the further processing of the biomass hydrolysate ina bioreforming process.

The product stream resulting from the biomass deconstruction willgenerally include water, unreacted or under-reacted product, ash and abiomass hydrolysate that includes lignin and lignocellulosicderivatives, cellulose and cellulosic derivatives, hemicellulose andhemicellulosic derivatives, carbohydrates, starches, monosaccharides,disaccharides, polysaccharides, sugars, sugar alcohols, alditols,polyols and mixtures thereof. Preferably, the biomass hydrolysateincludes sugar, sugar alcohols, starch, saccharides and other polyhydricalcohols. More preferably, the biomass hydrolysate includes a sugar,such as glucose, fructose, sucrose, maltose, lactose, mannose or xylose,or a sugar alcohol, such as arabitol, erythritol, glycerol, isomalt,lactitol, malitol, mannitol, sorbitol, xylitol, arabitol, or glycol. Incertain embodiments, the biomass hydrolysate may also include alcohols,ketones, cyclic ethers, esters, carboxylic acids, aldehydes, diols andother polyols that are useful as the processing solvent. In otherembodiments, the biomass hydrolysate may also include mono-oxygenatedhydrocarbons that may be further converted to C₄₊ hydrocarbons, such asC₄₊ alkanes, C₄₊ alkenes, and aromatic compounds, including benzene,toluene, xylene, which are useful as liquid fuels and chemicals.

The resulting biomass hydrolysate may be collected for furtherprocessing in a bioreforming process or, alternatively, used as afeedstock for other conversion processes, including the production offuels and chemicals using fermentation or enzymatic technologies. Forexample, water-soluble carbohydrates, such as starch, monosaccharides,disaccharides, polysaccharides, sugars, and sugar alcohols, andwater-soluble derivatives from the lignin, hemicellulose and celluloseare suitable for use in bioreforming processes. Alternatively, theresulting biomass hydrolysate may be recycled and combined in thebiomass slurry for further conversion or use as a processing solvent.

In certain applications, the biomass product stream undergoes one ormore separation steps to separate the ash, unreacted biomass andunder-reacted biomass from the product stream to provide the biomasshydrolysate. The biomass hydrolysate may also require further processingto separate aqueous phase products from organic phase products, such aslignin-based hydrocarbons not suitable for bioreforming processes. Thebiomass hydrolysate may also be dewatered or further purified prior tobeing introduced into the bioreforming process. Such dewatering andpurification processes are known in the art and may include simulatedmoving bed technology, distillation, filtration, etc.

Biomass Processing Solvent

Bioreforming processes convert starches, sugars and other polyols to awide range of oxygenates, including organic compounds that facilitatebiomass deconstruction. As used herein, “oxygenates” generically refersto hydrocarbon compounds having 2 or more carbon atoms and 1, 2 or 3oxygen atoms (referred to herein as C₂₊O₁₋₃ hydrocarbons), such asalcohols, ketones, aldehydes, hydroxy carboxylic acids, carboxylicacids, cyclic ethers, esters, diols and triols. Preferably, theoxygenates have from 2 to 6 carbon atoms, or 3 to 6 carbon atoms.Alcohols may include, without limitation, primary, secondary, linear,branched or cyclic C₂₊ alcohols, such as ethanol, n-propyl alcohol,isopropyl alcohol, butyl alcohol, isobutyl alcohol, butanol, pentanol,cyclopentanol, hexanol, cyclohexanol, 2-methyl-cyclopentanonol,heptanol, octanol, nonanol, decanol, undecanol, dodecanol, and isomersthereof. The ketones may include, without limitation, hydroxyketones,cyclic ketones, diketones, acetone, propanone, 2-oxopropanal, butanone,butane-2,3-dione, 3-hydroxybutan-2-one, pentanone, cyclopentanone,pentane-2,3-dione, pentane-2,4-dione, hexanone, cyclohexanone,2-methyl-cyclopentanone, heptanone, octanone, nonanone, decanone,undecanone, dodecanone, methylglyoxal, butanedione, pentanedione,diketohexane, and isomers thereof. The aldehydes may include, withoutlimitation, hydroxyaldehydes, acetaldehyde, propionaldehyde,butyraldehyde, pentanal, hexanal, heptanal, octanal, nonal, decanal,undecanal, dodecanal, and isomers thereof. The carboxylic acids mayinclude, without limitation, formic acid, acetic acid, propionic acid,butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, isomersand derivatives thereof, including hydroxylated derivatives, such as2-hydroxybutanoic acid and lactic acid. The diols may include, withoutlimitation, ethylene glycol, propylene glycol, 1,3-propanediol,butanediol, pentanediol, hexanediol, heptanediol, octanediol,nonanediol, decanediol, undecanediol, dodecanediol, lactones, andisomers thereof. The triols may include, without limitation, glycerol,1,1,1 tris(hydroxymethyl)-ethane (trimethylolethane),trimethylolpropane, hexanetriol, and isomers thereof. Cyclic ethersinclude, without limitation, furan, furfural, tetrahydrofuran,dihydrofuran, 2-furan methanol, 2-methyl-tetrahydrofuran,2,5-dimethyl-tetrahydrofuran, 2-methyl furan, 2-ethyl-tetrahydrofuran,2-ethyl furan, hydroxylmethylfurfural, 3-hydroxytetrahydrofuran,tetrahydro-3-furanol, 2,5-dimethyl furan,5-hydroxymethyl-2(5H)-furanone,dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydro-2-furoic acid,dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydrofurfuryl alcohol,1-(2-furyl)ethanol, hydroxymethyltetrahydrofurfural, and isomersthereof.

The above oxygenates may originate from any source, but are preferablyderived from oxygenated hydrocarbons resulting from the initialprocessing of the biomass in the biomass slurry. Oxygenated hydrocarbonsmay be any water-soluble oxygenated hydrocarbon having two or morecarbon atoms and at least one oxygen atom (referred to herein as C₂₊O₁₊hydrocarbons). Preferably, the oxygenated hydrocarbon has 2 to 12 carbonatoms (C₁₋₁₂O₁₋₁₁ hydrocarbon), and more preferably 2 to 6 carbon atoms(C₁₋₆O₁₋₆ hydrocarbon), and 1, 2, 3, 4, 5, 6 or more oxygen atoms. Theoxygenated hydrocarbon may also have an oxygen-to-carbon ratio rangingfrom 0.5:1 to 1.5:1, including ratios of 0.75:1.0, 1.0:1.0, 1.25:1.0,1.5:1.0, and other ratios between. In one example, the oxygenatedhydrocarbon has an oxygen-to-carbon ratio of 1:1. Nonlimiting examplesof preferred water-soluble oxygenated hydrocarbons include starches,monosaccharides, disaccharides, polysaccharides, sugar, sugar alcohols,alditols, ethanediol, ethanedione, acetic acid, propanol, propanediol,propionic acid, glycerol, glyceraldehyde, dihydroxyacetone, lactic acid,pyruvic acid, malonic acid, butanediols, butanoic acid, aldotetroses,tautaric acid, aldopentoses, aldohexoses, ketotetroses, ketopentoses,ketohexoses, alditols, hemicelluloses, cellulosic derivatives,lignocellulosic derivatives, starches, polyols and the like. Preferably,the oxygenated hydrocarbon includes starches, sugar, sugar alcohols,saccharides and other polyhydric alcohols. More preferably, theoxygenated hydrocarbon is a sugar, such as glucose, fructose, sucrose,maltose, lactose, mannose or xylose, or a sugar alcohol, such asarabitol, erythritol, glycerol, isomalt, lactitol, malitol, mannitol,sorbitol, xylitol, ribitol, or glycol.

Production of the Biomass Processing Solvent

As shown in Table 1 below, the bioreforming process produces a complexorganic mixture. The mixture of different organics provides goodcandidate compounds for a high quality biomass deconstruction solvent.

TABLE 1 Typical Products of a Bioreforming Process Aqueous Phase OrganicPhase % of % of Component Phase Component Phase 2-Pentanone 13.753-Hexanone 12.98 Butanoic acid 13.61 2-Hexanone 12.60 2-Butanone 13.082-Pentanone 9.53 Furan, tetrahydro-2,5- 10.70 Water 6.64 dimethyl-Butanoic acid 6.19 Acetone 8.43 2-Furanmethanol, tetrahydro- 5.68Propionic Acid 8.15 Furan, tetrahydro-2,5-dimethyl- 5.29 Acetic acid4.82 3-Pentanone 4.93 Pentanoic acid 4.68 Pentanoic acid 4.41 2-Butanol,(.+/−.)- 3.77 2-Butanone 4.35 2-Hexanone 3.75 2H-Pyran,tetrahydro-2-methyl- 2.78 3-Hexanone 3.57 2-Hexanol 2.22(R)-(—)-2-Pentanol 1.82 Hexanoic acid 2.10 Isopropyl Alcohol 1.73 Furan,tetrahydro-2-methyl- 1.95 Hexanoic acid 1.09 2(3H)-Furanone, 5- 1.712-Butanone, 3-hydroxy- 1.05 ethyldihydro- 2-Pentanol 1.71 3-Hexanol 1.62Hexane 1.55 Pentane 1.52 Propionic Acid 1.42

The oxygenates are prepared by reacting an aqueous feedstock solutioncontaining water and the water-soluble oxygenated hydrocarbons withhydrogen over a catalytic material to produce the desired oxygenates.The hydrogen may be generated in situ using aqueous phase reforming (insitu generated H₂ or APR H₂), or a combination of APR H₂, external H₂ orrecycled H₂, or just simply external H₂ or recycled H₂. The term“external H₂” refers to hydrogen that does not originate from thefeedstock solution, but is added to the reactor system from an externalsource. The term “recycled H₂” refers to unconsumed hydrogen, which iscollected and then recycled back into the reactor system for furtheruse. External H₂ and recycled H₂ may also be referred to collectively orindividually as “supplemental H₂.” In general, supplemental H₂ may beadded for purposes of supplementing the APR hydrogen or to increase thereaction pressure within the system, or to increase the molar ratio ofhydrogen to carbon and/or oxygen in order to enhance the productionyield of certain reaction product types, such as ketones and alcohols.

In processes utilizing APR H₂, the oxygenates are prepared bycatalytically reacting a portion of the aqueous feedstock solutioncontaining water and the water-soluble oxygenated hydrocarbons in thepresence of an APR catalyst at a reforming temperature and reformingpressure to produce the APR H₂, and catalytically reacting the APR H₂(and recycled H₂ and/or external H₂) with a portion of the feedstocksolution in the presence of a deoxygenation catalyst at a deoxygenationtemperature and deoxygenation pressure to produce the desiredoxygenates. In systems utilizing recycled H₂ or external H₂ as ahydrogen source, the oxygenates are simply prepared by catalyticallyreacting the recycled H₂ and/or external H₂ with the feedstock solutionin the presence of the deoxygenation catalyst at the deoxygenationtemperatures and pressures. In each of the above, the oxygenates mayalso include recycled oxygenates (recycled C₂₊O₁₋₃ hydrocarbons).

The deoxygenation catalyst is preferably a heterogeneous catalyst havingone or more active materials capable of catalyzing a reaction betweenhydrogen and the oxygenated hydrocarbon to remove one or more of theoxygen atoms from the oxygenated hydrocarbon to produce alcohols,ketones, aldehydes, cyclic ethers, esters, carboxylic acids, hydroxycarboxylic acids, diols and triols. In general, the heterogeneousdeoxygenation catalyst will have both an active metal function and anacidic function to achieve the foregoing. For example, acidic supports(e.g., supports having low isoelectric points) first catalyzedehydration reactions of oxygenated compounds. Hydrogenation reactionsthen occur on the metallic catalyst in the presence of H₂, producingcarbon atoms that are not bonded to oxygen atoms. The bi-functionaldehydration/hydrogenation pathway consumes H₂ and leads to thesubsequent formation of various polyols, diols, ketones, aldehydes,alcohols, carboxylic acids, hydroxy carboxylic acids and cyclic ethers,such as furans and pyrans.

The active materials may include, without limitation, Cu, Re, Fe, Ru,Ir, Co, Rh, Pt, Pd, Ni, W, Os, Mo, Ag, Au, alloys thereof, andcombinations thereof, adhered to a support. The deoxygenation catalystmay include these elements alone or in combination with one or more Mn,Cr, Mo, W, V, Nb, Ta, Ti, Zr, Y, La, Sc, Zn, Cd, Ag, Au, Sn, Ge, P, Al,Ga, In, Tl, Ce, and combinations thereof. In one embodiment, thedeoxygenation catalyst includes Pt, Pd, Ru, Re, Ni, W or Mo. In yetanother embodiment, the deoxygenation catalyst includes Sn, W, Mo, Ag,Fe and/or Re and at least one transition metal selected from Ni, Pd, Ptand Ru. In another embodiment, the catalyst includes Fe, Re and at leastCu or one Group VIIIB transition metal. In yet another embodiment, thedeoxygenation catalyst includes Pd alloyed or admixed with Cu or Ag andsupported on an acidic support. In yet another embodiment, thedeoxygenation catalyst includes Pd alloyed or admixed with a Group VIBmetal supported on an acidic support. In yet another embodiment, thedeoxygenation catalyst includes Pd alloyed or admixed with a Group VIBmetal and a Group IVA metal on an acidic support. The support may be anyone of a number of supports, including a support having carbon, silica,alumina, zirconia, titania, tungsten, vanadia, chromia, zeolites,heteropolyacids, kieselguhr, hydroxyapatite, and mixtures thereof.

The deoxygenation catalyst may include an acidic support modified orconstructed to provide the desired functionality. Heteropolyacids are aclass of solid-phase acids exemplified by such species asH_(3+x)PMo_(12-x)V_(x)O₄₀, H₄SiW₁₂O₄₀, H₃PW₁₂O₄₀, and H₆P2W₁₈O₆₂.Heteropolyacids are solid-phase acids having a well-defined localstructure, the most common of which is the tungsten-based Kegginstructure. Other examples may include, without limitation, tungstatedzirconia, tungsten modified zirconia, tungsten modified alpha-alumina,or tungsten modified theta alumina.

Loading of the first element (i.e., Cu, Re, Fe, Ru, Ir, Co, Rh, Pt, Pd,Ni, W, Os, Mo, Ag, Au, alloys and combinations thereof) is in the rangeof 0.25 wt % to 25 wt % on carbon, with weight percentages of 0.10% and0.05% increments between, such as 1.00%, 1.10%, 1.15%, 2.00%, 2.50%,5.00%, 10.00%, 12.50%, 15.00% and 20.00%. The preferred atomic ratio ofthe second element (i.e., Mn, Cr, Mo, W, V, Nb, Ta, Ti, Zr, Y, La, Sc,Zn, Cd, Ag, Au, Sn, Ge, P, Al, Ga, In, Tl, Ce, and combinations thereof)is in the range of 0.25-to-1 to 10-to-1, including any ratios between,such as 0.50, 1.00, 2.50, 5.00, and 7.50-to-1. If the catalyst isadhered to a support, the combination of the catalyst and the support isfrom 0.25 wt % to 10 wt % of the primary element.

To produce oxygenates, the oxygenated hydrocarbon is combined with waterto provide an aqueous feedstock solution having a concentrationeffective for causing the formation of the desired reaction products.The water-to-carbon ratio on a molar basis is preferably from about0.5:1 to about 100:1, including ratios such as 1:1, 2:1, 3:1, 4:1, 5:1,6:1, 7:1, 8:1, 9:1, 10:1, 15:1, 25:1, 50:1 75:1, 100:1, and any ratiosthere-between. The feedstock solution may also be characterized as asolution having at least 1.0 weight percent (wt %) of the total solutionas an oxygenated hydrocarbon. For instance, the solution may include oneor more oxygenated hydrocarbons, with the total concentration of theoxygenated hydrocarbons in the solution being at least about 1%, 5%,10%, 20%, 30%, 40%, 50%, 60%, 70%, 80% or greater by weight, includingany percentages between, and depending on the oxygenated hydrocarbonsused. In one embodiment, the feedstock solution includes at least about10%, 20%, 30%, 40%, 50%, or 60% of a sugar, such as glucose, fructose,sucrose or xylose, or a sugar alcohol, such as sorbitol, mannitol,glycerol or xylitol, by weight. Water-to-carbon ratios and percentagesoutside of the above stated ranges are also included. Preferably thebalance of the feedstock solution is water. In some embodiments, thefeedstock solution consists essentially of water, one or more oxygenatedhydrocarbons and, optionally, one or more feedstock modifiers describedherein, such as alkali or hydroxides of alkali or alkali earth salts oracids. The feedstock solution may also include recycled oxygenatedhydrocarbons recycled from the reactor system. The feedstock solutionmay also contain negligible amounts of hydrogen, preferably less thanabout 1.5 mole of hydrogen per mole of feedstock.

The feedstock solution is reacted with hydrogen in the presence of thedeoxygenation catalyst at deoxygenation temperature and pressureconditions, and weight hourly space velocity, effective to produce thedesired oxygenates. The specific oxygenates produced will depend onvarious factors, including the feedstock solution, reaction temperature,reaction pressure, water concentration, hydrogen concentration, thereactivity of the catalyst, and the flow rate of the feedstock solutionas it affects the space velocity (the mass/volume of reactant per unitof catalyst per unit of time), gas hourly space velocity (GHSV), andweight hourly space velocity (WHSV). For example, an increase in flowrate, and thereby a reduction of feedstock exposure to the catalystsover time, will limit the extent of the reactions which may occur,thereby causing increased yield for higher level diols and triols, witha reduction in ketone and alcohol yields.

The deoxygenation temperature and pressure are preferably selected tomaintain at least a portion of the feedstock in the liquid phase at thereactor inlet. It is recognized, however, that temperature and pressureconditions may also be selected to more favorably produce the desiredproducts in the vapor-phase or in a mixed phase having both a liquid andvapor phase. In general, the reaction should be conducted at processconditions wherein the thermodynamics of the proposed reaction arefavorable. For instance, the minimum pressure required to maintain aportion of the feedstock in the liquid phase will likely vary with thereaction temperature. As temperatures increase, higher pressures willgenerally be required to maintain the feedstock in the liquid phase, ifdesired. Pressures above that required to maintain the feedstock in theliquid phase (i.e., vapor-phase) are also suitable operating conditions.

In general, the deoxygenation temperature should be greater than 120°C., or 150° C., or 180° C., or 200° C., and less than 325° C., or 300°C., or 280° C., or 260° C., or 240° C., or 220° C. The reaction pressureshould be greater than 200 psig, or 365 psig, or 500 psig or 600 psig,and less than 2500 psig, or 2250 psig, or 2000 psig, or 1800 psig, or1500 psig, or 1200 psig, or 1000 psig. In one embodiment, thedeoxygenation temperature is between about 150° C. and 300° C., orbetween about 200° C. and 280° C., or between about 220° C. and 260° C.,or between about 150° C. and 260° C. In another embodiment, thedeoxygenation pressure is between about 365 and 2500 psig, or betweenabout 500 and 2000 psig, or between about 600 and 1800 psig, or betweenabout 365 and 1500 psig.

A condensed liquid phase method may also be performed using a modifierthat increases the activity and/or stability of the catalyst system. Itis preferred that the water and the oxygenated hydrocarbon are reactedat a suitable pH of from about 1.0 to about 10.0, including pH values inincrements of 0.1 and 0.05 between, and more preferably at a pH of fromabout 4.0 to about 10.0. Generally, the modifier is added to thefeedstock solution in an amount ranging from about 0.1% to about 10% byweight as compared to the total weight of the catalyst system used,although amounts outside this range are included within the presentinvention.

In general, the reaction should be conducted under conditions where theresidence time of the feedstock solution over the catalyst isappropriate to generate the desired products. For example, the WHSV forthe reaction may be at least about 0.1 gram of oxygenated hydrocarbonper gram of catalyst per hour, and more preferably the WHSV is about 0.1to 40.0 g/g hr, including a WHSV of about 0.25, 0.5, 0.75, 1.0, 1.0,1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4,2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8,3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 20, 25, 30, 35, 40 g/g hr, and ratios between(including 0.83, 0.85, 0.85, 1.71, 1.72, 1.73, etc.).

The hydrogen used in the deoxygenation reaction may be in-situ-generatedH_(z), external H₂ or recycled H₂. The amount (moles) of external H₂ orrecycled H₂ introduced to the feedstock is between 0-100%, 0-95%, 0-90%,0-85%, 0-80%, 0-75%, 0-70%, 0-65%, 0-60%, 0-55%, 0-50%, 0-45%, 0-40%,0-35%, 0-30%, 0-25%, 0-20%, 0-15%, 0-10%, 0-5%, 0-2%, or 0-1% of thetotal number of moles of the oxygenated hydrocarbon(s) in the feedstock,including all intervals between. When the feedstock solution, or anyportion thereof, is reacted with APR hydrogen and external H₂ orrecycled H₂, the molar ratio of APR hydrogen to external H₂ (or recycledH₂) is at least 1:100, 1:50, 1:20; 1:15, 1:10, 1:5; 1:3, 1:2, 1:1, 2:1,3:1, 5:1, 10:1, 15:1, 20:1, 50:1, 100:1 and ratios between (including4:1, 6:1, 7:1, 8:1, 9:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1and 19:1, and vice-versa).

In-Situ Hydrogen Production

One advantage of the present invention is that it allows for theproduction and use of in-situ-generated H₂. The APR H₂ is produced fromthe feedstock under aqueous phase reforming conditions using an aqueousphase reforming catalyst (APR catalyst). The APR catalyst is preferablya heterogeneous catalyst capable of catalyzing the reaction of water andoxygenated hydrocarbons to form H₂ under the conditions described below.In one embodiment, the APR catalyst includes a support and at least oneGroup VIIIB metal, Fe, Ru, Ir, Co, Rh, Pt, Pd, Ni, alloys andcombinations thereof. The APR catalyst may also include at least oneadditional material from Group VIIIB, Group VIIB, Group VIB, Group VB,Group IVB, Group IIB, Group IB, Group IVA or Group VA metals, such asCu, B, Mn, Re, Cr, Mo, Bi, W, V, Nb, Ta, Ti, Zr, Y, La, Sc, Zn, Cd, Ag,Au, Sn, Ge, P, Al, Ga, In, Tl, Ce, alloys and combinations thereof. Thepreferred Group VIIB metal includes Re, Mn, or combinations thereof. Thepreferred Group VIB metal includes Cr, Mo, W, or a combination thereof.The preferred Group VIIIB metals include Pt, Rh, Ru, Pd, Ni, orcombinations thereof. The supports may include any one of the catalystsupports described below, depending on the desired activity of thecatalyst system.

The APR catalyst may also be atomically identical to the deoxygenationcatalyst. For instance, the APR and deoxygenation catalyst may includePt alloyed or admixed with Ni, Ru, Cu, Fe, Rh, Re, alloys andcombinations thereof. The APR catalyst and deoxygenation catalyst mayalso include Ru alloyed or admixed with Ge, Bi, B, Ni, Sn, Cu, Fe, Rh,Pt, alloys and combinations thereof. The APR catalyst may also includeNi alloyed or admixed with Sn, Ge, Bi, B, Cu, Re, Ru, Fe, alloys andcombinations thereof.

Preferred loading of the primary Group VIIIB metal is in the range of0.25 wt % to 25 wt % on carbon, with weight percentages of 0.10% and0.05% increments between, such as 1.00%, 1.10%, 1.15%, 2.00%, 2.50%,5.00%, 10.00%, 12.50%, 15.00% and 20.00%. The preferred atomic ratio ofthe second material is in the range of 0.25-to-1 to 10-to-1, includingratios between, such as 0.50, 1.00, 2.50, 5.00, and 7.50-to-1.

A preferred catalyst composition is further achieved by the addition ofoxides of Group IIIB, and associated rare earth oxides. In such event,the preferred components would be oxides of either lanthanum or cerium.The preferred atomic ratio of the Group IIIB compounds to the primaryGroup VIIIB metal is in the range of 0.25-to-1 to 10-to-1, includingratios between, such as 0.50, 1.00, 2.50, 5.00, and 7.50-to-1.

Another preferred catalyst composition is one containing platinum andrhenium. The preferred atomic ratio of Pt to Re is in the range of0.25-to-1 to 10-to-1, including ratios there-between, such as 0.50,1.00, 2.50, 5.00, and 7.00-to-1. The preferred loading of the Pt is inthe range of 0.25 wt % to 5.0 wt %, with weight percentages of 0.10% and0.05% between, such as 0.35%, 0.45%, 0.75%, 1.10%, 1.15%, 2.00%, 2.50%,3.0%, and 4.0%.

Preferably, the APR catalyst and the deoxygenation catalyst are of thesame atomic formulation. The catalysts may also be of differentformulations. The catalysts may also be a single catalyst with both APRand deoxygenation functionality provided by the combination of the abovedescribed APR materials and deoxygenation materials. In such event, thepreferred atomic ratio of the APR catalyst to the deoxygenation catalystis in the range of 5:1 to 1:5, such as, without limitation, 4.5:1,4.0:1, 3.5:1, 3.0:1, 2.5:1, 2.0:1, 1.5:1, 1:1, 1:1.5, 1:2.0, 1:2.5,1:3.0, 1:3.5, 1:4.0, 1:4.5, and any amounts between.

Similar to the deoxygenation reactions, the temperature and pressureconditions are preferably selected to maintain at least a portion of thefeedstock in the liquid phase at the reactor inlet. The reformingtemperature and pressure conditions may also be selected to morefavorably produce the desired products in the vapor-phase or in a mixedphase having both a liquid vapor phase. In general, the APR reactionshould be conducted at a temperature where the thermodynamics arefavorable. For instance, the minimum pressure required to maintain aportion of the feedstock in the liquid phase will vary with the reactiontemperature. As temperatures increase, higher pressures will generallybe required to maintain the feedstock in the liquid phase. Any pressureabove that required to maintain the feedstock in the liquid phase (i.e.,vapor-phase) is also a suitable operating pressure. For vapor phasereactions, the reaction should be conducted at a reforming temperaturewhere the vapor pressure of the oxygenated hydrocarbon compound is atleast about 0.1 atm (and preferably a good deal higher), and thethermodynamics of the reaction are favorable. The temperature will varydepending upon the specific oxygenated hydrocarbon compound used, but isgenerally in the range of from about 100° C. to 450° C., or from about100° C. to 300° C., for reactions taking place in the vapor phase. Forliquid phase reactions, the reaction temperature may be from about 80°C. to 400° C., and the reaction pressure from about 72 psig to 1300psig.

In one embodiment, the reaction temperature is between about 100° C. and400° C., or between about 120° C. and 300° C., or between about 200° C.and 280° C., or between about 150° C. and 270° C. The reaction pressureis preferably between about 72 and 1300 psig, or between about 72 and1200 psig, or between about 145 and 1200 psig, or between about 200 and725 psig, or between about 365 and 700 psig, or between about 600 and650 psig.

In embodiments where the APR catalyst and the deoxygenation catalyst arecombined into a single catalyst, or the reactions are conductedsimultaneously in a single reactor, the reforming temperature anddeoxygenation temperature may be in the range of about 100° C. to 325°C., or about 120° C. to 300° C., or about 200° C. to 280° C., and thereforming pressure and deoxygenation pressure may be in the range ofabout 200 psig to 1500 psig, or about 200 psig to 1200 psig, or about200 psig to 725 psig.

A condensed liquid phase method may also be performed using a modifierthat increases the activity and/or stability of the APR catalyst system.It is preferred that the water and the oxygenated hydrocarbon arereacted at a suitable pH of from about 1.0 to 10.0, or at a pH of fromabout 4.0 to 10.0, including pH value increments of 0.1 and 0.05between. Generally, the modifier is added to the feedstock solution inan amount ranging from about 0.1% to about 10% by weight as compared tothe total weight of the catalyst system used, although amounts outsidethis range are included within the present invention.

Alkali or alkali earth salts may also be added to the feedstock solutionto optimize the proportion of hydrogen in the reaction products.Examples of suitable water-soluble salts include one or more selectedfrom the group consisting of an alkali or an alkali earth metalhydroxide, carbonate, nitrate, or chloride salt. For example, addingalkali (basic) salts to provide a pH of about pH 4.0 to about pH 10.0can improve hydrogen selectivity of reforming reactions.

The addition of acidic compounds may also provide increased selectivityto the desired reaction products in the hydrogenation reactionsdescribed below. It is preferred that the water-soluble acid is selectedfrom the group consisting of nitrate, phosphate, sulfate, chloridesalts, and mixtures thereof. If an acidic modifier is used, it ispreferred that it be present in an amount sufficient to lower the pH ofthe aqueous feed stream to a value between about pH 1.0 and about pH4.0. Lowering the pH of a feed stream in this manner may increase theproportion of oxygenates in the final reaction products.

In general, the reaction should be conducted under conditions where theresidence time of the feedstock solution over the APR catalyst isappropriate to generate an amount of APR hydrogen sufficient to reactwith a second portion of the feedstock solution over the deoxygenationcatalyst to provide the desired oxygenates. For example, the WHSV forthe reaction may be at least about 0.1 gram of oxygenated hydrocarbonper gram of APR catalyst, and preferably between about 1.0 to 40.0 gramsof oxygenated hydrocarbon per gram of APR catalyst, and more preferablybetween about 0.5 to 8.0 grams of oxygenated hydrocarbon per gram of APRcatalyst. In terms of scaled-up production, after start-up, the APRreactor system should be process controlled so that the reactionsproceed at steady-state equilibrium.

Biomass Processing Solvent with C₄₊ Compounds

The biomass processing solvent or solvent mixture may also include C₄₊compounds derived from the further processing of the oxygenates. In suchapplications, oxygenates are further converted into C₄₊ compounds bycondensation in the presence of a condensation catalyst. Thecondensation catalyst will generally be a catalyst capable of forminglonger chain compounds by linking two oxygen containing species througha new carbon-carbon bond, and converting the resulting compound to ahydrocarbon, alcohol or ketone, such as an acid catalyst, basic catalystor a multi-functional catalyst having both acid and base functionality.The condensation catalyst may include, without limitation, carbides,nitrides, zirconia, alumina, silica, aluminosilicates, phosphates,zeolites, titanium oxides, zinc oxides, vanadium oxides, lanthanumoxides, yttrium oxides, scandium oxides, magnesium oxides, ceriumoxides, barium oxides, calcium oxides, hydroxides, heteropolyacids,inorganic acids, acid modified resins, base modified resins, andcombinations thereof. The condensation catalyst may include the abovealone or in combination with a modifier, such as Ce, La, Y, Sc, P, B,Bi, Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, and combinations thereof. Thecondensation catalyst may also include a metal, such as Cu, Ag, Au, Pt,Ni, Fe, Co, Ru, Zn, Cd, Ga, In, Rh, Pd, Ir, Re, Mn, Cr, Mo, W, Sn, Os,alloys and combinations thereof, to provide a metal functionality. Thecondensation catalyst may also be atomically identical to the APRcatalyst and/or the deoxygenation catalyst, or combined in a singlecatalytic form to provide the APR and/or deoxygenation and/orcondensation functionality.

The condensation catalyst may be self-supporting (i.e., the catalystdoes not need another material to serve as a support), or may require aseparate support suitable for suspending the catalyst in the reactantstream. One particularly beneficial support is silica, especially silicahaving a high surface area (greater than 100 square meters per gram),obtained by sol-gel synthesis, precipitation or fuming. In otherembodiments, particularly when the condensation catalyst is a powder,the catalyst system may include a binder to assist in forming thecatalyst into a desirable catalyst shape. Applicable forming processesinclude extrusion, pelletization, oil dropping, or other knownprocesses. Zinc oxide, alumina, and a peptizing agent may also be mixedtogether and extruded to produce a formed material. After drying, thismaterial is calcined at a temperature appropriate for formation of thecatalytically active phase, which usually requires temperatures inexcess of 450° C.

In certain applications, the condensation reaction is performed usingacidic catalysts. The acid catalysts may include, without limitation,aluminosilicates (zeolites), silica-alumina phosphates (SAPO), aluminumphosphates (ALPO), amorphous silica alumina, zirconia, sulfatedzirconia, tungstated zirconia, tungsten carbide, molybdenum carbide,titania, acidic alumina, phosphated alumina, phosphated silica, sulfatedcarbons, phosphated carbons, acidic resins, heteropolyacids, inorganicacids, and combinations thereof. In one embodiment, the catalyst mayalso include a modifier, such as Ce, Y, Sc, La, P, B, Bi, Li, Na, K, Rb,Cs, Mg, Ca, Sr, Ba, and combinations thereof. The catalyst may also bemodified by the addition of a metal, such as Cu, Ag, Au, Pt, Ni, Fe, Co,Ru, Zn, Cd, Ga, In, Rh, Pd, Ir, Re, Mn, Cr, Mo, W, Sn, Os, alloys andcombinations thereof, to provide metal functionality, and/or sulfidesand oxide of Ti, Zr, V, Nb, Ta, Mo, Cr, W, Mn, Re, Al, Ga, In, Fe, Co,Ir, Ni, Si, Cu, Zn, Sn, Cd, P, and combinations thereof. Gallium hasalso been found to be particularly useful as a promoter for the presentprocess. The acid catalyst may be homogenous, self-supporting or adheredto any one of the supports further described below, including supportscontaining carbon, silica, alumina, zirconia, titania, vanadia, ceria,nitride, boron nitride, heteropolyacids, alloys and mixtures thereof.

Ga, In, Zn, Fe, Mo, Ag, Au, Ni, P, Sc, Y, Ta, and lanthanides may alsobe exchanged onto zeolites to provide a zeolite catalyst havingactivity. The term “zeolite” as used herein refers not only tomicroporous crystalline aluminosilicate but also for microporouscrystalline metal-containing aluminosilicate structures, such asgalloaluminosilicates and gallosilicates. Metal functionality may beprovided by metals such as Cu, Ag, Au, Pt, Ni, Fe, Co, Ru, Zn, Cd, Ga,In, Rh, Pd, Ir, Re, Mn, Cr, Mo, W, Sn, Os, alloys and combinationsthereof.

Examples of suitable zeolite catalysts include ZSM-5, ZSM-11, ZSM-12,ZSM-22, ZSM-23, ZSM-35 and ZSM-48. Zeolite ZSM-5, and the conventionalpreparation thereof, is described in U.S. Pat. Nos. 3,702,886; Re.29,948 (highly siliceous ZSM-5); U.S. Pat. Nos. 4,100,262 and 4,139,600,all incorporated herein by reference. Zeolite ZSM-11, and theconventional preparation thereof, is described in U.S. Pat. No.3,709,979, which is also incorporated herein by reference. ZeoliteZSM-12, and the conventional preparation thereof, is described in U.S.Pat. No. 3,832,449, incorporated herein by reference. Zeolite ZSM-23,and the conventional preparation thereof, is described in U.S. Pat. No.4,076,842, incorporated herein by reference. Zeolite ZSM-35, and theconventional preparation thereof, is described in U.S. Pat. No.4,016,245, incorporated herein by reference. Another preparation ofZSM-35 is described in U.S. Pat. No. 4,107,195, the disclosure of whichis incorporated herein by reference. ZSM-48, and the conventionalpreparation thereof, is taught by U.S. Pat. No. 4,375,573, incorporatedherein by reference. Other examples of zeolite catalysts are describedin U.S. Pat. No. 5,019,663 and U.S. Pat. No. 7,022,888, alsoincorporated herein by reference.

As described in U.S. Pat. No. 7,022,888, the acid catalyst may be abifunctional pentasil zeolite catalyst including at least one metallicelement from the group of Cu, Ag, Au, Pt, Ni, Fe, Co, Ru, Zn, Cd, Ga,In, Rh, Pd, Ir, Re, Mn, Cr, Mo, W, Sn, Os, alloys and combinationsthereof, or a modifier from the group of Ga, In, Zn, Fe, Mo, Au, Ag, Y,Sc, Ni, P, Ta, lanthanides, and combinations thereof. The zeolitepreferably has a strong acidic and dehydrogenation sites, and may beused with reactant streams containing and an oxygenated hydrocarbon at atemperature of below 500° C. The bifunctional pentasil zeolite may haveZSM-5, ZSM-8 or ZSM-11 type crystal structure consisting of a largenumber of 5-membered oxygen-rings, i.e., pentasil rings. The zeolitewith ZSM-5 type structure is a particularly preferred catalyst. Thebifunctional pentasil zeolite catalyst is preferably Ga and/orIn-modified ZSM-5 type zeolites such as Ga and/or In-impregnatedH-ZSM-5, Ga and/or In-exchanged H-ZSM-5, H-gallosilicate of ZSM-5 typestructure and H-galloaluminosilicate of ZSM-5 type structure. Thebifunctional ZSM-5 type pentasil zeolite may contain tetrahedralaluminum and/or gallium present in the zeolite framework or lattice andoctahedral gallium or indium. The octahedral sites are preferably notpresent in the zeolite framework but are present in the zeolite channelsin a close vicinity of the zeolitic protonic acid sites, which areattributed to the presence of tetrahedral aluminum and gallium in thezeolite. The tetrahedral or framework Al and/or Ga is believed to beresponsible for the acid function of zeolite and octahedral ornon-framework Ga and/or In is believed to be responsible for thedehydrogenation function of the zeolite.

In one embodiment, the condensation catalyst may be aH-galloaluminosilicate of ZSM-5 type bifunctional pentasil zeolitehaving framework (tetrahedral) Si/Al and Si/Ga mole ratio of about10-100 and 15-150, respectively, and non-framework (octahedral) Ga ofabout 0.5-5.0 wt. %. When these pentasil H-galloaluminosilicate zeolitesare used as a condensation catalyst, the density of strong acid sitescan be controlled by the framework Al/Si mole ratio: the higher theAl/Si ratio, the higher the density of strong acid sites. The highlydispersed non-framework gallium oxide species can be obtained by thedegalliation of the zeolite by its pre-treatment with H₂ and steam. Thezeolite containing strong acid sites with high density and also highlydispersed non-framework gallium oxide species in close proximity of thezeolite acid site is preferred. The catalyst may optionally contain anybinder such as alumina, silica or clay material. The catalyst can beused in the form of pellets, extrudates and particles of differentshapes and sizes.

The acidic catalysts may include one or more zeolite structurescomprising cage-like structures of silica-alumina. Zeolites arecrystalline microporous materials with well-defined pore structure.Zeolites contain active sites, usually acid sites, which can begenerated in the zeolite framework. The strength and concentration ofthe active sites can be tailored for particular applications. Examplesof suitable zeolites for condensing secondary alcohols and alkanes maycomprise aluminosilicates optionally modified with cations, such as Ga,In, Zn, Mo, and mixtures of such cations, as described, for example, inU.S. Pat. No. 3,702,886, which is incorporated herein by reference. Asrecognized in the art, the structure of the particular zeolite orzeolites may be altered to provide different amounts of varioushydrocarbon species in the product mixture. Depending on the structureof the zeolite catalyst, the product mixture may contain various amountsof aromatic and cyclic hydrocarbons.

Alternatively, solid acid catalysts such as alumina modified withphosphates, chloride, silica, and other acidic oxides could be used inpracticing the present invention. Also, either sulfated zirconia ortungstated zirconia may provide the necessary acidity. Re and Pt/Recatalysts are also useful for promoting condensation of oxygenates toC₅₊ hydrocarbons and/or C₅₊ mono-oxygenates. The Re is sufficientlyacidic to promote acid-catalyzed condensation. Acidity may also be addedto activated carbon by the addition of either sulfates or phosphates.

The condensation reactions result in the production of C₄₊ alkanes, C₄₊alkenes, C₅₊ cycloalkanes, C₅₊ cycloalkenes, aryls, fused aryls, C₄₊alcohols, C₄₊ ketones, and mixtures thereof. The C₄₊ alkanes and C₄₊alkenes have from 4 to 30 carbon atoms (C₄₋₃₀ alkanes and C₄₋₃₀ alkenes)and may be branched or straight chained alkanes or alkenes. The C₄₊alkanes and C₄₊ alkenes may also include fractions of C₄₋₉, C₇₋₁₄,C₁₂₋₂₄ alkanes and alkenes, respectively, with the C₄₋₉ fractiondirected to gasoline, the C₇₋₁₄ fraction directed to jet fuels, and theC₁₂₋₂₄ fraction directed to diesel fuel and other industrialapplications. Examples of various C₄₊ alkanes and C₄₊ alkenes include,without limitation, butane, butane, pentane, pentene, 2-methylbutane,hexane, hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane,2,3-dimethylbutane, heptane, heptene, octane, octene,2,2,4,-trimethylpentane, 2,3-dimethyl hexane, 2,3,4-trimethylpentane,2,3-dimethylpentane, nonane, nonene, decane, decene, undecane, undecene,dodecane, dodecene, tridecane, tridecene, tetradecane, tetradecene,pentadecane, pentadecene, hexadecane, hexadecane, heptyldecane,heptyldecene, octyldecane, octyldecene, nonyldecane, nonyldecene,eicosane, eicosene, uneicosane, uneicosene, doeicosane, doeicosene,trieicosane, trieicosene, tetraeicosane, tetraeicosene, and isomersthereof.

The C₅₊ cycloalkanes and C₅₊ cycloalkenes have from 5 to 30 carbon atomsand may be unsubstituted, mono-substituted or multi-substituted. In thecase of mono-substituted and multi-substituted compounds, thesubstituted group may include a branched C₃₊ alkyl, a straight chain C₁₊alkyl, a branched C₃₊ alkylene, a straight chain C₁₊ alkylene, astraight chain C₂₊ alkylene, a phenyl or a combination thereof. In oneembodiment, at least one of the substituted groups include a branchedC₃₋₁₂ alkyl, a straight chain C₁₋₁₂ alkyl, a branched C₃₋₁₂ alkylene, astraight chain C₁₋₁₂ alkylene, a straight chain C₂₋₁₂ alkylene, a phenylor a combination thereof. In yet another embodiment, at least one of thesubstituted groups include a branched C₃₋₄ alkyl, a straight chain C₁₋₄alkyl, a branched C₃₋₄ alkylene, straight chain C₁₋₄ alkylene, straightchain C₂₋₄ alkylene, a phenyl or a combination thereof. Examples ofdesirable C₅₊ cycloalkanes and C₅₊ cycloalkenes include, withoutlimitation, cyclopentane, cyclopentene, cyclohexane, cyclohexene,methyl-cyclopentane, methyl-cyclopentene, ethyl-cyclopentane,ethyl-cyclopentene, ethyl-cyclohexane, ethyl-cyclohexene, and isomersthereof.

Biomass Deconstruction

In the deconstruction process, the biomass slurry is combined with thebiomass processing solvent described above and reacted to form a biomasshydrolysate. Preferably the biomass slurry comprises 10-50% of thefeedstock. The biomass slurry may include any type of biomass, includingbut not limited to chopped or ground solids, microcrystalline or cottoncellulose, wood or non-wood lignocelluloses, recycle fibers such asnewspaper and paperboard, forest and agricultural waste residues,including sawdust, bagasse, and corn stover, and energy crops, such asmiscanthus, switch grass, sorghum and others. The biomass processingsolvent contains a wide range of oxygenates as described above.

The deconstruction process can be either batch or continuous. In oneembodiment, the deconstruction is a continuous process using one or morecontinuous stirred-tank reactors in parallel or in series. Thedeconstruction temperature will generally be greater than 80° C., or120° C., or 150° C., or 180° C., or 250° C., and less than 350° C., or325° C., or 300° C., or 260° C. In one embodiment, the deconstructiontemperature is between about 80° C. and 350° C., or between about 120°C. and 300° C., or between about 150° C. and 260° C., or between about180° C. and 260° C.

The deconstruction pressure is generally greater than 100 psi, or 250psi, or 300 psi, or 625 psi, or 900 psi, or 1000 psi, or 1200 psi, andless than 2000 psi, or 1500 psi, or 1200 psi. In one embodiment, thedeconstruction temperature is between about 300 psi and 2000 psi, orbetween about 300 psi and 1500 psi, or between about 1000 psi and 1500psi. Preferably, the slurry contacts the solvent for betweenapproximately 5 minutes and 2 hours.

The deconstruction process fractionates and solubilizes a portion of thecellulose, lignin and hemicellulose originating in the biomass. Throughthis process, lignin, cellulose and hemicellulose decompose tocarbohydrates, starches, monosaccharides, disaccharides,polysaccharides, sugars, sugar alcohols, alditols, polyols and mixturesthereof. Unreacted components can be separated through phase separationwith minimal cross contamination.

Dewatering of the Biomass Hydolyzate

The biomass hydrolysate product stream contains large amounts of water,which may impact reactor size, catalyst activity and overallcost-effectiveness of the process. As a result, dewatering the biomasshydrolysate may create more favorable conditions for downstreambioreforming process reactions. Suitable dewatering processes are knownin the art and include wet classification, centrifugation, filtration,or similar solid-liquid separation processes.

Recycling of Biomass Processing Solvent

As shown above, the bioreforming process produces a complex mixture oforganic compounds. In one embodiment, after completing a bioreformingprocess such as APR and/or HDO, various process streams can be separatedand recycled for use as the biomass processing solvent or directed tofurther processing for conversion to liquid fuels and chemicals.

In one embodiment, the products from the APR/HDO processes can beseparated based on the thermodynamic properties (e.g., boiling point) ofthe oxygenates using standard fractionation techniques. In suchapplication, the more volatile compounds are separated from a bottomstream containing heavier and less volatile compounds. This heavy bottomstream includes some of the components listed in Table 1 above. Theheavy bottom stream can be divided such that some of the heavy bottomstream is recycled into the bioreforming process to undergo furtherprocessing, with the remainder of the heavy bottom stream recycled tomix with the biomass slurry prior to the deconstruction process. Theorganic compounds in the heavy bottom stream help dissolve and cracklignin, which improves lignin removal from the biomass slurry.

In another embodiment of the present invention, an effluent stream canbe separated from the bioreforming product stream. This effluent streamincludes the organic phase components listed in Table 1, as well as someof the aqueous phase components listed in Table 1. The effluent streamcan be recycled to mix with the biomass slurry prior to thedeconstruction process. The residual organic acids in the effluentstream can improve biomass deconstruction.

In certain embodiments, the biomass deconstruction and the bioreformingprocess may be conducted simultaneously in a single reactor. An exampleof such a reactor is a slurry reactor wherein the biomass is introducedin a first end with a recycle stream that includes both unreacted orunder-reacted biomass and biomass processing solvent collected from alater heavy bottom stream. In such applications, the biomass processingsolvent promotes biomass deconstruction, which in turn providesoxygenated hydrocarbons for conversion into oxygenates by thedeoxygenation catalyst in the reactor. A portion of the oxygenates, inturn, may be either maintained in the reactor, recycled for use as abiomass processing solvent and/or further processed to provide liquidfuels and chemicals.

The biomass deconstruction process described herein efficiently utilizesthe available components in lignocellulosic biomass by hydrolyzing thelignin, cellulose and hemicellulose to provide water-soluble oxygenatedhydrocarbons for further use in bioreforming processes. The biomassdeconstruction process reduces biomass deconstruction costs by avoidingthe need to purchase expensive deconstruction solvents and by avoidingsolvent recovery and clean-up costs by recycling solvent fromintermediates produced in bioreforming processes. The biomassdeconstruction process also provides a bioreforming stream bysolubilizing lignin, cellulose and hemicellulose components into useablecarbohydrates, starches, monosaccharides, disaccharides,polysaccharides, sugars, sugar alcohols, alditols, polyols and mixturesthereof.

Example 1

A preliminary deconstruction trial was conducted using a mixture ofbioreforming organic phase products. The solvent was composed of 60 wt %bioreforming organic phase materials and 40 wt % deionized water. Abiomass slurry having a biomass concentration of 5 wt % sugarcanebagasse in solvent was reacted over a period of two hours at atemperature of 180° C. in an autoclave reactor. The reaction resulted in40% conversion of the sugarcane bagasse to organic and aqueous phaseproducts, with low lignin content fibers as residual solids. The visibledelignification effects indicated that the complex organic mixture fromthe bioreforming process contains compounds useful as a highly efficientdeconstruction solvent.

Example 2

Experimental results of initial biomass deconstruction using benzene,toluene, and 4-methyl-2-pentanone are shown in FIG. 3. Reactionconditions were 10% bagasse, 170° C., 500 psi N2, 30 min heating, 30 minretention. Solvent was mixed with water to give the target weightpercent as depicted in FIG. 3. With the high concentration solvent, someof the lignin was deconstructed, producing liquid form products.

Example 3

A deconstruction trial was conducted using APR aqueous products, themajor compounds of which are shown in FIG. 4, as a solvent to liquefylignin residue derived from a separated enzymatic hydrolysate of cornstover. 10.0 g of lignin was loaded in a batch reactor with 100 g of APRaqueous products. The reactor was sealed and pressurized to 101.6 psi(at room temperature) with nitrogen and stirred at 800 RPM. The slurrywas heated to 190° C. (at pressure of 330 psi) and soaked for 90minutes. Lignin was 100% liquefied at the end of experiment producingliquid phase biomass hydrolysate, indicating that the APR aqueousproducts contains compounds useful as a highly efficient deconstructionsolvent.

1. A method of making a biomass hydrolysate, the method comprising: A.catalytically reacting water and a water-soluble C₂₊O₁₊ oxygenatedhydrocarbon in a liquid or vapor phase with H₂ in the presence of adeoxygenation catalyst at a deoxygenation temperature and adeoxygenation pressure to produce a biomass processing solventcomprising a C₂₊O₁₋₃ hydrocarbon in a reaction stream, wherein thebiomass processing solvent comprises a member selected from the groupconsisting of an alcohol, ketone, aldehyde, cyclic ether, ester, diol,triol, hydroxy carboxylic acid, carboxylic acid, and a mixture thereof;and B. reacting the biomass processing solvent with a solid biomasscomponent at a deconstruction temperature and a deconstruction pressureto produce a biomass hydrolysate comprising at least one member selectedfrom the group consisting of a water-soluble lignocellulose derivative,a water-soluble cellulose derivative, a water-soluble hemicellulosederivative, a carbohydrate, a starch, a monosaccharide, a disaccharide,a polysaccharide, a sugar, a sugar alcohol, an alditol and a polyol. 2.A method of deconstructing biomass, the method comprising reacting abiomass slurry with a biomass processing solvent comprising a C₂₊O₁₋₃hydrocarbon, wherein the biomass processing solvent comprises a memberselected from the group consisting of an alcohol, ketone, aldehyde,diol, triol, cyclic ether, ester, hydroxy carboxylic acid, carboxylicacid, and a mixture thereof, at a deconstruction temperature betweenabout 80° C. and 350° C. and a deconstruction pressure between about 100psi and 2000 psi to produce a biomass hydrolysate comprising at leastone member selected from the group consisting of a water-solublelignocellulose derivative, water-soluble cellulose derivative,water-soluble hemicellulose derivative, carbohydrate, starch,monosaccharide, disaccharide, polysaccharide, sugar, sugar alcohol,alditol, and polyol, wherein the biomass processing solvent is producedby catalytically reacting in the liquid or vapor phase an aqueousfeedstock solution comprising water and a water-soluble oxygenatedhydrocarbons comprising a C₂₊O₁₊ hydrocarbon with H₂ in the presence ofa deoxygenation catalyst at a deoxygenation temperature anddeoxygenation pressure.
 3. The method of claim 2, wherein the oxygenatedhydrocarbon comprises a member selected from the group consisting of alignocellulose derivative, a cellulose derivative, a hemicellulosederivative, a carbohydrate, a starch, a monosaccharide, a disaccharide,a polysaccharide, a sugar, a sugar alcohol, an alditol, and a polyol. 4.The method of claim 2, wherein the biomass hydrolysate is recycled andcombined with the biomass slurry.
 5. The method of claim 2, wherein thebiomass processing solvent comprises a member selected from the groupconsisting of methanol, ethanol, n-propyl alcohol, isopropyl alcohol,butyl alcohol, pentanol, hexanol, cyclopentanol, cyclohexanol,2-methylcyclopentanol, a hydroxyketone, a cyclic ketone, acetone,propanone, butanone, pentanone, hexanone, 2-methyl-cyclopentanone,ethylene glycol, 1,3-propanediol, propylene glycol, butanediol,pentanediol, hexanediol, methylglyoxal, butanedione, pentanedione,diketohexane, a hydroxyaldehyde, acetaldehyde, propionaldehyde,butyraldehyde, pentanal, hexanal, formic acid, acetic acid, propionicacid, butanoic acid, pentanoic acid, hexanoic acid, lactic acid,glycerol, furan, tetrahydrofuran, dihydrofuran, 2-furan methanol,2-methyl-tetrahydrofuran, 2,5-dimethyl-tetrahydrofuran,2-ethyl-tetrahydrofuran, 2-methyl furan, 2,5-dimethyl furan, 2-ethylfuran, hydroxylmethylfurfural, 3-hydroxytetrahydrofuran,tetrahydro-3-furanol, 5-hydroxymethyl-2(5H)-furanone,dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydro-2-furoic acid,dihydro-5-(hydroxymethyl)-2(3H)-furanone, tetrahydrofurfuryl alcohol,1-(2-furyl)ethanol, and hydroxymethyltetrahydrofurfural, isomersthereof, and combinations thereof.
 6. The method of claim 2, wherein thedeoxygenation catalyst comprises a support and a member adhered to thesupport wherein, the member is selected from the group consisting of Re,Cu, Fe, Ru, Ir, Co, Rh, Pt, Pd, Ni, W, Os, Mo, Ag, Au, an alloy thereof,and a combination thereof.
 7. The method of claim 2, wherein thedeoxygenation catalyst further comprises a member selected from thegroup consisting of Mn, Cr, Mo, W, V, Nb, Ta, Ti, Zr, Y, La, Sc, Zn, Cd,Ag, Au, Sn, Ge, P, Al, Ga, In, Tl, alloys thereof, and combinationsthereof.
 8. The method of claim 6, wherein the support comprises amember selected from group consisting of a carbon, silica, alumina,zirconia, titania, vanadia, heteropolyacid, kieselguhr, hydroxyapatite,chromia, zeolite, and mixtures thereof.
 9. The method of claim 8,wherein the support is selected from the group consisting of tungstatedzirconia, tungsten modified zirconia, tungsten modified alpha-alumina,or tungsten modified theta alumina.
 10. The method of claim 2, whereinthe deoxygenation temperature is in the range of about 120° C. to 325°C., and the deoxygenation pressure is at least 0.1 atmosphere.
 11. Themethod of claim 2, wherein the deoxygenation temperature is in the rangeof about 200° C. to 280° C., and the deoxygenation pressure betweenabout 600 psig and 1800 psig.
 12. The method of claim 2, wherein thedeoxygenation temperature is greater than 120° C., or 150° C., or 180°C., or 200° C., and less than 325° C., or 300° C., or 280° C., or 260°C., or 240° C., or 220° C.
 13. The method of claim 2, wherein thedeoxygenation pressure is greater than 200 psig, or 365 psig, or 500psig or 600 psig, and less than 2500 psig, or 2250 psig, or 2000 psig,or 1800 psig, or 1500 psig, or 1200 psig, or 1000 psig.
 14. The methodof claim 2, wherein the step of reacting a biomass slurry with a biomassprocessing solvent is performed in the same reactor as the step ofcatalytically reacting the aqueous feedstock solution with H₂ in thepresence of a deoxygenation catalyst.
 15. The method of claim 2 furtherincluding the step of dewatering the biomass hydrolysate.